The ATmega328PB is a low-power CMOS 8-bit microcontroller based on the AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the ATmega328PB achieves throughputs close to 1 MIPS per MHz. This empowers system designer to optimize the device for power consumption versus processing speed.

The core combines a rich instruction set with 32 general purpose working registers. All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in a single instruction executed in one clock cycle. The resulting architecture is more code efficient while achieving throughputs up to ten times faster than conventional CISC microcontrollers.

The ATmega328PB provides the following features: 32 KB of In-System Programmable Flash with Read-While-Write capabilities, 1 KB EEPROM, 2 KB SRAM, 27 general purpose I/O lines, 32 general purpose working registers, five flexible Timer/Counters with compare modes, internal and external interrupts, two serial programmable USART, two byte-oriented two-wire Serial Interface (I2C), two SPI serial ports, an 8-channel 10-bit ADC in TQFP and QFN/MLF package, a programmable Watchdog Timer with internal Oscillator, Clock failure detection mechanism, and six software selectable power saving modes. The Idle mode stops the CPU while allowing the SRAM, Timer/Counters, USART, two-wire Serial Interface, SPI port, and interrupt system to continue functioning. PTC with enabling up to 24 self-cap and 144 mutual-cap sensors. The Power-Down mode saves the register contents but freezes the Oscillator, disabling all other chip functions until the next interrupt or hardware reset. In Power-Save mode, the asynchronous timer continues to run, allowing the user to maintain a timer base while the rest of the device is sleeping. Also ability to run PTC in Power-Save mode/wake-up on touch and Dynamic ON/OFF of PTC analog and digital portion. The ADC Noise Reduction mode stops the CPU and all I/O modules except asynchronous timer, PTC, and ADC to minimize switching noise during ADC conversions. In Standby mode, the crystal/resonator Oscillator is running while the rest of the device is sleeping. This allows very fast start-up combined with low power consumption.

The device is manufactured using high-density non-volatile memory technology. The On-chip ISP Flash allows the program memory to be reprogrammed In-System through an SPI serial interface, by a conventional nonvolatile memory programmer or by an On-chip Boot program running on the AVR core. The Boot program can use any interface to download the application program in the Application Flash memory. Software in the Boot Flash section will continue to run while the Application Flash section is updated, providing true Read-While-Write operation. By combining an 8-bit RISC CPU with In-System Self-Programmable Flash on a monolithic chip, the ATmega328PB is a powerful microcontroller that provides a highly flexible and cost-effective solution to many embedded control applications.

The ATmega328PB is supported by a full suite of program and system development tools including C Compilers, Macro Assemblers, Program Debugger/Simulators, In-Circuit Emulators, and Evaluation kits.